Method of coloring pile fabrics



Dec. 31, 1968 F. A. EUFORBIA METHOD OF COLORING PILE FABRICS Sheet FiledOct. 28, 1965 FELIX AVEUFOIZBIA ATTORNEYS 31, 1% F. A. EUFORBIA3,419,413

METHOD OF COLORING FILE FABRICS Filed 001,. 28, 1965 Sheet 2 of 2INVENTORI FELIX A. EUF-ORBlA ATTORNEYS Uited States Patent 3,419,413METHOD OF COLORING PILE FABRICS Felix A. Euforbia, Greensboro, N.C.,assignor to Foremost Screen Print, Inc., Stokesdale, N.C., a corporationof Delaware Filed Oct. 28, 1965, Ser. No. 505,516 Claims. (Cl. 11738)ABSTRACT OF THE DISCLOSURE lateral spreading of the colorant to obtainthe final design of a predetermined size.

This invention relates to the art of obtaining colored or printeddesigns on pile fabrics such as tufted or Woven, looped, mapped or cutpile fabrics, including carpet, rug, blanket and terry fabrics, and isespecially concerned with effecting the coloring of very thick pilematerials to substantially the base of the piles for obtaining depth ofcolor comparing aesthetically favorably with predyed pile yarns.

Many and varied attempts have been made heretofore to print on pilefabric surfaces. While some methods or apparatuses of the prior art havebeen successful in producing printed design areas on the pile fabrics,considerable difficulties have been experienced in effecting substantialpenetration of the pile with the ink, especially in very small or narrowareas and particularly in deep pile. One known method has includedimmersing each of a plurality of pile areas in liquid coloring matter orink contained in configured receptacles. However, such a method isexpensive and time consuming, requires the manufacture and storing ofmany different shaped receptacles and becomes impractical in printingvery small or narrow pile areas.

The application of suction to the lower surface of a pile fabric duringthe application of liquid pigments or dyes to the pile surface through aprinting screen is also known, but requires bulky and expensiveequipment not normally required and has not, to my knowledge, beeneffective to cause the desired penetration of ink to the base of highpile with proper line definition, particularly in the coloring of verysmall or narrow design areas.

Attempts have been made to force ink into pile utilizing successivescreens or stencils beneath which the pile fabric was advanced in astepwise manner with ink distributing rollers moving across and againstthe screens to distribute ink through permeable areas of the screenswhile applying heavy downward pressure to the screens and to the piletherebeneath. However, such attempts have not been successful to myknowledge because, if sufficient downward pressure is applied to aprinting screen by ink distributing means such as to force ink topenetrate downwardly into pile beneath the screen, an objectionableexcessive and uneven lateral distribution of the ink occurs between thescreen and the face of the pile so the required definition of coloreddesigns on the pile cannot be obtained. The lateral distribution of inkat narrow design areas is particularly objectionable, especially inmulticolor printing, because the color printed at one screen may beoverlapped, or possibly hidden, by the color printed on a juxtaposedpile area at a succeeding screen; i.e., the colored designs would beimproperly registered and of blurred appearance.

It is therefore an object of this invention to provide a novel,economical method of printing designs on a thick or high pile fabric andwhich is particularly effective in printing very small or narrow designareas with the ink effectively penetrating the pile at such areas to adepth heretofore unattainable to my knowledge.

It is another object of this invention to provide a method of printingdesigns on fabric having high projecting pile which comprises applyingink to predetermined areas of the pile, and thereafter compressing thepile with the ink thereon to force the ink to penetrate from the face ofthe pile substantially to the base of the pile.

The method, as disclosed in detail hereinafter, includes positioning aprojecting pile surface beneath a screen having one or more permeableareas therein, after which a squeegee blade is moved along and againstthe screen for distributing colored ink thereover and through thepermeable areas to deposit ink on and form corresponding design areas onthe pile surface and, thereafter, the pile surface is removed frombeneath the screen and compressed under heavy pressure to force thedeposited ink thereon to penetrate the pile surface substantially to thebase of the pile.

Some of the objects having been stated, other objects will appear as thedescription proceeds, when taken in connection with the accompanyingdrawings, in which- FIGURE 1 is a schematic perspective view of anembodiment of apparatus for carrying out the method of this invention; 1

FIGURE 2 is an enlarged side view of the upper portion of the pilecompressing apparatus in the right-hand portion of FIGURE 1;

FIGURE 3 is an enlarged fragmentary detail showing how the pile iscompressed as it passes through the squeeze rolls;

FIGURES 4 and 5 are fragmentary plan views of a fine-line design area onthe pile surface of a pile fabric before and after the ink has beenforced to penetrate the pile;

FIGURES 6 and 7 are enlarged sectional views taken along lines 6-6 and77 in respective FIGURES 4 and 5;

FIGURE 8 is a fragmentary vertical sectional view taken substantiallyalong line 8-8 in FIGURE 1 and illustrating a typical squeegee fordistributing ink along the corresponding pinting screen and FIGURE 9 isa schematic view showing an alternative embodiment of means forcompressing the pile surface.

Referring more specifically to the drawings, apparatus for carrying outthe printing method according to the invention may comprise a stencilprinting or screen printing system having one or more printing stationsfor printing different colored design areas on fabric therebeneath,there being two such stations P, P shown successively arranged in FIGURE1 which may be of conventional or other construction. Fabric 10, havingprojecting pile surfaces or sections 11 thereon, may be drawn from asuitable supply roll 12 along the upper surface of a table 13 by anintermittently driven endless conveyor or belt 14 whose upper run, withpile fabric 10 thereon, extends between the printing stencils or screens15, 16 or stations P, P and table 13, through the space between squeezerolls 20, 21 of a novel pile compressing unit 22, and into a suitablefinishing means 23 which may take the form of a dryer or ager, or whichmay be arranged to subject the fabric to additional wet treatmentsaccording to the characteristics of the ink or colorant applied to thepile surfaces 11, as is well known in the art.

The term ink or colorant is used herein to indicate generically any typeof colored solution or paste suitable for use in stencil printing orscreen printing intricate design areas on textile fabric or pilesurfaces thereon and including pigments in emulsion form or solubledyes, such as vat dyes, mixed with a starch or flour paste, or with gumpaste. Pigments are preferred in many instances because, after thefabric has been printed with pigment emulsion and dried, furtherfinishing treatments may not be required. However, further treatment isrequired after printing with soluble dyes so as to remove starch orother material previously mixed with the dye.

Conveyor 14 may be mounted on rollers 25, 26 and may be driven by anysuitable indexing drive means well known in the art to advancesuccessive pile surfaces 11 into registration with printing stations P,P, allowing time between successive advancements of conveyor 14 forapplication of ink to corresponding pile surfaces at printing stationsP, P. As shown in FIGURE 1, the indexing drive means may include asuitably controlled single-revolution clutch means 30 for intermittentlytransmitting rotation from a motor 31 through belt and pulley means 32to conveyor roller 25.

Printing stations P, P comprise respective stencils or screens made fromwoven cloth of nylon, silk or the like which is impermeable by the inkbeing used with the exception of permeable pattern areas or openings 36,36' formed in the screens. Masses of ink C, C are distributed over therespective screens and through pattern areas 36, 36' onto pile surfaces11 therebeneath by respective squeegees 40, 40' which are shown as beingof the blade type which are preferable over rollers because, as is wellknown, squeegee blades effect a clearer definition of inked designs thanrollers, especially in fine-line work. As shown, the squeegees are movedacross and against screens 35, 35' by suitable linkages 41, 41 operatingin timed relation to stepwise advancement of conveyor 14, as is wellknown. Both Squeegees 40, 40' should comprise a thin resilient blade,made from rubber or the like, such as is shown in FIGURE 8, to insurethat the squeegees cause effective penetration of the ink through allpermeable pattern areas 36, 36', and, especially, through very small ornarrow pattern areas such as areas 36 of screen 35, for example.

Screens 35, 35' are mounted in taut condition on suitable frames 43, 43which are raised during each advancement of conveyor 14 and fabric bysuitable means of well known construction generally designated at 44,44', the screens 35, 35 being lowered against corresponding pilesurfaces during the dwell between successive advancements of conveyor14. With the exception of pile compressing unit 22, the apparatusheretofore described may be conventional and, therefore, a detailedillustration and description thereof is deemed unnecessary. However,suitable means for advancing the fabric 10, raising and lowering screens35, 35 and reciprocating Squeegees 40, 40' in proper timed relationshipare disclosed more in detail in Gorners U.S. Patent No. 1,815,504 datedJuly 21, 1931, to which reference is made by way of example.

According to the method of the instant invention, the essential novelstep in effectively coloring predetermined areas of the projecting pilesurface substantially to the base of the pile resides in compressing thepile surface after ink has been applied to predetermined areas of thepile surface at a printing station or stations and following removal ofthe pile surface from the printing station or stations, and wherein themagnitude of such compression is such as to force the ink to penetratefrom the face of the pile surface substantially to the base of theprojecting pile. Since compressing the pile forces ink at the tipsthereof to penetrate downwardly into the pile, this improves the handand feel of the pile fabric at the design areas. The pile compressingunit 22 is one representative embodiment of means for compressingsuccessive pile surfaces 11 and comprises a frame including a pair ofstandards 50 spaced forwardly of printing stations P, P adjacentopposite sides of conveyor 14 and in which reduced opposite ends oflower squeeze roll 21 are journaled.

Bearing blocks 51 are guided for vertical movement in bifurcated upperportions of standards 50 and have reduced opposite ends of upper squeezeroll 20 journaled therein. As illustrated, each bearing block 51 isconnected to a ram or piston rod 52 of a fluid motor or double-actingfluid cylinder 53 fixed on a bridging upper portion 54 of thecorresponding standard and having a piston 55 therein to which the upperend of the corresponding piston rod 52 is connected. Upper and lowerends of cylinders 53 may be connected to a suitable source of fluidpressure, not shown, by means of respective upper and lower conduits 56,57. A suitable four-way valve 58 may be interposed in conduits 56, 57 soroll 20 may be raised and lowered at the will of the operator. In thisarrangement, it is desirable that piston rods 52 apply downward pressureof from about 2500 to 3500 pounds per square inch to upper squeeze roll20. However, a gap G is formed at the nip of rolls 20, 21 (see FIGURE3), due to adjustable limiting means which may comprise a screw 60threaded into each standard 50 at the bottom of its bifurcated upperportion and against which the corresponding bearing block 51 is normallyheld by piston rod 52. Thus, it can be seen that the width of gap G maybe readily adjusted by adjusting screws 60. Each screw 60 may beprovided with a lock nut 61. The width of gap G should be such that roll20 is supported by the pile of fabric 10 during movement of the fabricthrough the squeeze rolls. In other words, the width of the gap shouldbe substantially less than the height of the pile combined with thethickness of the fabric base and the belt 14. The gap G aids in thefeeding of the fabric 10 into the squeeze rolls. Particularly,maintenance of gap G prevents upper squeeze roll 20 from bouncing andsmearing the pile sections 11 as they enter and leave rolls 20, 21. Inpractice, it has been found that the ideal width of gap G without fabricextending therethrough can best be determined empirically, since thewidth of gap G may vary according to the type of yarn of which the pileis formed, the type or viscosity of printing ink applied to the face ofthe pile, and the density and height of the pile. For example, inprocessing a fine denier filamentary or staple pile surface, in whichthe pile yarn was made of textile filaments or fibers in the range ofabout one-thousandths to twenty-thousandths inch diameter and the heightof the pile was in the range of about threeeighths to three-fourthsinch, the gap G was about onesixteenth inch wide, plus the combinedthickness of the fabric base and conveyor 14. For processing a coarserpile made from pile yarns in the range of about twentyfive thousandthsto three-sixteenths inch diameter with a pile height of from one-half toone inch, the gap G was about three-sixteenths inch wide plus thecombined thickness of the fabric base on conveyor 14. The amount ofdownward force applied to roll 20 is not critical as long as it issufficient to insure sufiicient compression of the pile to causepenetration of ink substantially to the base of the pile.

Any suitable means may be provided for driving squeeze rolls 20, 21 atabout the same surface speed as, and at the same time as, conveyor 14.As shown, pulleys 65, 6, fixed on squeeze rolls 20, 21, are engaged byan endless belt 67 held taut by an adjustable idler 70, and pulleys 71,72, 73, 74, endless belts 75, 76 and a jack shaft 77 serve to connectbottom squeeze roll 21 to the output side of clutch means 30.

The amount of ink deposited on the pile surfaces at each printingstation P, P is determined by the viscosity of the ink C, C and theangular position of squeegees 40, 40', as is usual. The amount of inkrequired to be deposited at stations P, P should be accuratelydetermined empirically for a given type and construction of pile fabricso the compressing unit 22 will force all the ink previously depositedto penetrate substantially to the base of the pile without leavingexcess reidual ink on the tips of the piles. However, since the ink iswet during the compressing of the pile, a thin film of ink may adhere toupper squeeze roll 20 and should be removed therefrom so that it is notredeposited on the pile surface. Accordingly, the periphery of roll 20is engaged by one or more doctor blades 78, there being two such doctorblades shown in FIGURE 2 suitably adjustably secured to and extendingbetween standards 50. Any ink scraped off roll 20 may be occasionallymanually or automatically wiped off blades 78.

In the method described up to this point, it can be appreciated that, inthe interim between successive advancements of conveyor 14 and fabric10, screens 35, 35 are lowered against corresponding pile surfaces 11,and Squeegees 40, 40 are moved across screens 35, 35 to distribute inkof the desired viscosity across the screens and through respectivepermeable pattern areas 36, 36' to form respective, different coloreddesign areas 36A, 36A (FIGURE 1) of ink on the corresponding pilesurfaces. Thereafter, screens 35, 35 are raised, and conveyor 14advances fabric another step to expose the pile surface 14 upon whichink C' was last printed at station P.

The operation of printing stations P, P is then repeated. As eachadvancement of conveyor 14 occurs, a pile surface 11, to which ink hasbeen previously applied, passes through squeeze rolls 20, 21 so thepressure of upper squeeze roll against the pile surface compresses thesame to some extent and forces the ink, which is still wet, to penetratefrom the upper face of the pile to the base thereof. In the course ofcompressing the pile with ink thereon, although most of the ink isforced downwardly toward the fabric base, a small proportion of the inkis spread laterally so the ultimate size of the design areas on the pilesurfaces is slightly greater than the size they were initially formed atprinting stations P, P. In instances in which the design areas are quitelarge and/ or close registration of adjacent design areas isunnecessary, or if the entire pile surface is to be of a solid color,the small amount of lateral spreading of the ink effected by compressingthe pile is not objectionable and generally would not detract from theaesthetic quality of the fabric, because the ink previously has been soapplied to the pile surface as to form sharp, clean design areas thereonand the compressing of the pile by means of a hard smooth surface causessubstantially uniform spreading of the ink in all lateral directions.

However, when relatively close registration of adjacent design areas isrequired, or design areas are to be quite small, or fine-line narrowdesign areas of as little as three thirty-seconds inch wide or less areto be formed, such as the areas 36A of FIGURES 1 and 5, I havecompensative- 1y reduced the size of, or under-cut, the pattern areas 36in screen by about one thirty-second to one-sixteenth of an inchdepending upon the height and density of the pile to be printed. Thus,upon initially applying ink to the pile at printing station P, thenarrow-line design areas 36A are of somewhat lesser width than thedesired ultimate width thereof. Upon subsequently compressing the pilesurface by passing the fabric through squeeze rolls 20, 21, for example,the design areas 36A are spread laterally to become the desired ultimatewidth. One of the design areas 36A is shown on a portion of acorresponding pile surface 11 before and after compression of the pilesurface in respective FIGURES 4 and 5 wherein it will be observed thatthe lines of design area 36A are quite narrow in FIGURE 4; e.g., aboutthree sixty-fourths inch wide, and the lines of the same design area36A, as shown in FIGURE 5 after compressing the pile, are about threethirty-seconds inch wide. This phenomenon is further illustrated on alarger scale in FIGURES 6 and 7. In FIGURE 6 it will be observed thatthe ink is deposited in a narrow layer upon the pile 11 and penetratesonly the tips of the pile tufts there beneath. After compressing thepile, however, it will be observed in FIGURE 7 that the ink has spreadlaterally in the design area 36A and penetrates the pile from the tipsof the pile tufts substantially to the base thereof.

As is well known, the lesser the density of the piles, the longer thepile tufts, and the softer the pile surface, the greater is the tendencyfor the piles to bend so their free ends may lay generally parallel tothe lateral plane of the fabric, such as is shown in FIGURES 3, 6 and 7.Although the piles are shown bending or inclining in FIG- URES 3, 6 and7, it will be appreciated that there are many pile fabrics whose piletufts are so densely arranged or are made of such pile yarns that theywill not normally be inclined in the manner illustrated in FIGURES 3, 6and 7. In the case of pile fabrics whose piles remain substantiallyerect, it is apparent that they will be erect both before and after theyare compressed. As is the case with the particular type of fabricillustrated in FIGURES 6 and 7, the clear definition of color designareas is also obtained when processing substantially erect-pile fabricsin accordance with the method of this invention. In most pile fabricswhose piles bend substantially as illustrated in FIGURES 3, 6 and 7,most of the piles naturally bend in the same direction. It has beenfound that the uniformity of dispersion of the ink in the design areasand clear definition of the design areas of such bent-pile fabric isimproved by advancing the fabric through squeeze ro'lls 20, 21 with thetips of the piles pointing toward the direction of movement of thefabric so the ink is forced toward the bases of the piles rather thantoward the tips of the piles. In some bent-pile fabrics, the piles donot lay generally in the same direction and, therefore, I have providedsuitable means for brushing such fabrics and which may comprise a rotarybrush (FIGURE 1) suitably journ'aied on table 13 to extend across andabove conveyor 14 nearwardly of printing station P so as to engage andcomb the pile surfaces 11 in the direction of advancement thereof. Brush80 may be provided with stiff bristles 81, as shown, or with cardclothing wire or any other suitable covering effective to cause thepiles to lay in the direction of advancement thereof along conveyor 14.Brush 80 may be driven at such speed as to effect the desired brushingof the piles by any suitable drive means. As shown, pulley and belt@means 83 serve to connect conveyor roller 25 to brush 80 so brush 80 isrotated only during each advancement of fabric 10. Brush 80 may beremoved or omitted in instances in which the pile surface need not bebrushed.

While the squeeze roll arrangement of FIGURES 1, 2 and 3 is a preferredembodiment of pile compressing means for carrying out the method of thisinvention, it is contemplated that other types of pile compressingdevices may be employed. For example, another type of pile compressingunit 22A is shown schematically in FIG- URE 9 which may be used in placeof the compressing unit 22 in FIGURE 1. Referring to FIGURE 9, conveyor14 with pile fabric 10 thereon is shown positioned upon table 13. Pilecompressing unit 22A comprises a vertically movable substantiallyhorizontal platen or pressure plate carried by a ram or piston rod 91connected to a piston 92 in a double-acting cylinder 93. Cylinder 93 isfixed to a cantilever frame 95 which extends outwardly and thendownwardly and is suitably secured to table 13. Upper and lower ends ofcylinder 93 may be connected to a suitable source of fluid pressure, notshown, by means of respective conduits 96, 97. A suitable four-way valve98 may be interposed in conduits 96, 97 to control the rais ing andlowering of platen 90. Valve 98 may 'be operated manually orautomatically to move platen 90 downwardly in the interim betweensuccessive advancements of conveyor 14 and to raise platen 90 duringeach advancement of conveyor 14. It can be seen that platen 90 willcompress the pile and force the ink thereon to penetrate substantiallyto the base of the pile each time platen 90 is moved into pressureengagement with a previously printed pile surface therebeneath. Suitableabutments 100 may be provided on table 113 in FIGURE 9 to limit downwardmovement of platen 90, if desired.

Although it is preferred that squeeze rolls 20, 21 of pile compressingunit 22 are provided with smooth, hard, cylindrical peripheral surfaces,either or both squeeze rolls 20, 21 may be provided with yieldablesurfaces, if desired, provided that such surfaces are capable ofperforming the desired function of squeeze rolls 20, 21 to compress thepile surface and force the ink to penetrate the pile to the base thereofwithout distorting the design areas printed thereon.

In the drawings and specification there have been set forth preferredembodiments of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaims.

I claim:

1. A method of obtaining colored designs even of a very intricate natureon pile fabric such as pile rugs wherein the colored design extendssubstantially throughout the depth of the pile and wherein the height ofthe pile is at least about inch, said method including screen printingcolorant in a predetermined design onto the face of the pile fabric withthe design being undersize as compared to the final design desired andwherein the printed colorant extends substantially less than the depthof the pile, thereafter moving the screen-printed fabric to acompression station and directing the same through a pair of squeezerolls to drive the colorant downwardly substantially throughout thedepth of the pile while effecting a lateral spreading of the colorant toobtain the final design of a predetermined size, and wiping the squeezeroll contacting the face of the fabric during passage of the fabricthrough the rolls to remove residual colorant therefrom to avoid colorinterference with the screen-printed design.

2. The method of claim 1 wherein the screen printing of colorant ontothe face of the pile fabric takes place at at least two stations andwherein different colorants are applied at the respective stations.

3. The method of claim 1 in which the pile fabric is passed through thesqueeze rolls with the pile of the fabric inclined generally toward thedirection of movement of the fabric.

4. The method of claim 1, which includes spacing the squeeze rolls apartfrom each other to form a gap between the rolls of a dimension less thanthe thickness of the pile fabric for facilitating initial threading ofthe pile fabric between the rolls and for facilitating applying thedesired pressure to the pile fabric passing therebetween.

5. The method of claim 1 in which the step of screen printing includesmoving a squeegee blade against a mass of colorant and across andagainst a screen positioned against the pile face of the fabric.

References Cited UNITED STATES PATENTS 1,771,341 7/1930 McCollum 117381,821,302 9/1931 Gorner 101129 X 2,135,711 11/1938 Hiers. 2,220,58911/1940 Unger. 2,816,811 12/1957 Tillett et a1 11737 3,121,642 2/1964-Biskup 117-15 RALPH S. KENDALL, Primary Examiner.

A. M. GRIMALDI, Assistant Examiner.

U.S. Cl. X.R.

